May in Kostino is the windiest month of the year. In May, the weather in Kostino is typically warm. Average daily high temperature in May is about 12 degrees above zero. On average, Kostino has 20 rainy, 5 cloudy, 4 sunny, and 2 partly cloudy days in May. The rains are usually moderate. May as well as January, February, April, and September is considered the most uncomfortable time to visit Kostino.